title: Right ventricular dysfunction in systemic sclerosis-associated pulmonary arterial hypertension.
abstract: BACKGROUND
  Systemic sclerosis–associated pulmonary artery hypertension (SScPAH) has a worse prognosis compared with idiopathic pulmonary arterial hypertension (IPAH), with a median survival of 3 years after diagnosis often caused by right ventricular (RV) failure. We tested whether SScPAH or systemic sclerosis–related pulmonary hypertension with interstitial lung disease imposes a greater pulmonary vascular load than IPAH and leads to worse RV contractile function.
  
  
  RESULTS
  We analyzed pulmonary artery pressures and mean flow in 282 patients with pulmonary hypertension (166 SScPAH, 49 systemic sclerosis–related pulmonary hypertension with interstitial lung disease, and 67 IPAH). An inverse relation between pulmonary resistance and compliance was similar for all 3 groups, with a near constant resistance×compliance product. RV pressure–volume loops were measured in a subset, IPAH (n=5) and SScPAH (n=7), as well as SSc without PH (n=7) to derive contractile indexes (end-systolic elastance [Ees] and preload recruitable stroke work [Msw]), measures of RV load (arterial elastance [Ea]), and RV pulmonary artery coupling (Ees/Ea). RV afterload was similar in SScPAH and IPAH (pulmonary vascular resistance=7.0±4.5 versus 7.9±4.3 Wood units; Ea=0.9±0.4 versus 1.2±0.5 mm Hg/mL; pulmonary arterial compliance=2.4±1.5 versus 1.7±1.1 mL/mm Hg; P>0.3 for each). Although SScPAH did not have greater vascular stiffening compared with IPAH, RV contractility was more depressed (Ees=0.8±0.3 versus 2.3±1.1, P<0.01; Msw=21±11 versus 45±16, P=0.01), with differential RV-PA uncoupling (Ees/Ea=1.0±0.5 versus 2.1±1.0; P=0.03). This ratio was higher in SSc without PH (Ees/Ea=2.3±1.2; P=0.02 versus SScPAH).
  
  
  CONCLUSIONS
  RV dysfunction is worse in SScPAH compared with IPAH at similar afterload, and may be because of intrinsic systolic function rather than enhanced pulmonary vascular resistive and pulsatile loading.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Tedford
authors.forename: James O
authors.initials: JO
authors.lastname: Mudd
authors.forename: Reda E
authors.initials: RE
authors.lastname: Girgis
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Mathai
authors.forename: Ari L
authors.initials: AL
authors.lastname: Zaiman
authors.forename: Traci
authors.initials: T
authors.lastname: Housten-Harris
authors.forename: Danielle
authors.initials: D
authors.lastname: Boyce
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Kelemen
authors.forename: Anita C
authors.initials: AC
authors.lastname: Bacher
authors.forename: Ami A
authors.initials: AA
authors.lastname: Shah
authors.forename: Laura K
authors.initials: LK
authors.lastname: Hummers
authors.forename: Fredrick M
authors.initials: FM
authors.lastname: Wigley
authors.forename: Stuart D
authors.initials: SD
authors.lastname: Russell
authors.forename: Rajeev
authors.initials: R
authors.lastname: Saggar
authors.forename: Rajan
authors.initials: R
authors.lastname: Saggar
authors.forename: W Lowell
authors.initials: WL
authors.lastname: Maughan
authors.forename: Paul M
authors.initials: PM
authors.lastname: Hassoun
authors.forename: David A
authors.initials: DA
authors.lastname: Kass
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D062186:Arterial Pressure; D006328:Cardiac Catheterization; D016009:Chi-Square Distribution; D003187:Compliance; D065627:Familial Primary Pulmonary Hypertension; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D016014:Linear Models; D017563:Lung Diseases, Interstitial / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D017711:Nonlinear Dynamics; D011237:Predictive Value of Tests; D011379:Prognosis; D011651:Pulmonary Artery / Q000503:physiopathology*; D011652:Pulmonary Circulation; D012307:Risk Factors; D012595:Scleroderma, Systemic / Q000150:complications*; D014481:United States; D014655:Vascular Resistance; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D016278:Ventricular Function, Right; D017725:Ventricular Pressure